"Good to know it's not frowned upon to be on LinkedIn while employed," wrote George. "I've always felt I was cheating on my boss whenever I spent time on that site at work. Now, I will treat it as something I do with my routine; first check e-mail, then Facebook, then LinkedIn. Thanks for the piece."

"I have over 500 connections on LinkedIn, and now I'm thinking that might be too high," wrote A.J. "I can't call them all on the phone like your article said, but I thought the point was to get to know them better so maybe one day you could? Now I'm confused."

Kenny agreed with our expert that getting too personal on LinkedIn is a bad idea.

"My friend had some photos from a birthday party where he was with several scantily clad women! I told him he should take them down and he thought they would make him look more appealing to be photographed with several hot chicks. Instead he looked like a playboy," Kenny wrote.

"I'm more than glad to accept request from former co-workers, so long as I actually worked with them," says Matt. "Oftentimes this kind of contact allows me to help make connections to those that would benefit each other, and to get the word out about those looking for new opportunities—selectively—to my network."

Mary liked our expert's use of the made-up word "profersonal" when describing how social media sites blend our professional and personal lives.

"I'm trying to use LinkedIn more for professional reasons and Facebook for social, although I don't think I would get too social on LinkedIn. Time to rewrite my summary! Great advice."

"I can't agree more about hiring a writer for your summary," says Jonathan. "I have been appalled at the level of incompetence I find in some of the profiles on LinkedIn. I was considering a connection with a highly respected professional, and decided not to pursue after reading his description of his own accomplishments. Get a professional to do it right or don't do it at all."

And finally, Craig says he doesn't like the fact that LinkedIn has fees.

"Linked in is fine except to the unemployed with scarce funds available," he wrote. "They give you one to two months free and then erase all the information after that. I found that disconcerting after compiling recommendations from co-workers."

I checked with our LinkedIn expert, Jason Seiden of Ajax Social Media, to see if this was the case, and he says that LinkedIn is free unless you choose to make upgrades.

"And there's no need to upgrade unless you're a recruiter or business development executive," Seiden says, because a basic account does everything the average user needs.